On the 5th they were again driven back from the Hermada and San Giovanni, while away in the north they failed to take the heights of Lom. This held up their further advance across the Bainsizza plateau, and its eastern half, containing peaks a thousand feet higher than any the Italians had conquered, remained in Austrian hands. No real progress had been made, the partial occupation of the Bainsizza plateau proved useless, the losses had been tremendous, and at the end of September Cadorna reported that his main operations were at an end. Eleven of the sixteen British batteries were recalled, the French were countermanded, and the ball was left at Ludendorff's feet. He had begun his preparations in August when Otto von Buelow was transferred from the West to the Italian front and given an army composed of six German and seven Austrian divisions. The control of the campaign was taken over by the German Higher Command, and the troops had been trained in the new tactics which were tried by Von Hutier at Riga in the first week in September and were to be used to more serious purpose at Caporetto in October and on the Western front in 1918. Time was of the essence of Ludendorff's strategy; he could not afford, with the American peril in prospect, to prolong the war by fighting in trenches and merely defending the Hindenburg lines. Nor could he even afford that deliberate method of progress favoured by Haig and Pétain, which consisted in rapid advances on limited fronts to limited objectives, or in snail-like movements over wider areas. The strategy which by intense bombardment drove the enemy back a mile or two at the cost of so devastating the ground as to make one's own advance impossible for weeks, could not achieve a decision within the time at Ludendorff's disposal. Some means must be found of reviving the war of movement and repeating in a more decisive form the German march of August 1914. The bombardment of devastation must therefore be sacrificed in the interests of the pursuing troops, and its place be taken by gas shells; and the enemy line must be broken by the superiority of picked battalions and greater concentration of machine guns and other portable weapons. The line once broken, the advantage must be followed up by a series of fresh divisions passing through and beyond the others like successive waves, maintaining the continuity of the flowing tide. The Eastern front was used as a training ground for these new tactics, which served Ludendorff better than any advance into Russia could have done; and they came as a complete surprise at Caporetto.